Silver nanoparticles passivated with aniline and their subsequent polymerization using hematin as a catalyst

In this work, silver nanoparticles (AgNPs) were synthesized via two different routes. The first route was based on the Creighton method (chemical reduction), used aniline as a passivating agent and NaBH4 as a reducing agent, and led to a green nanoparticle solution with an average particle size of 23 ​± ​11 ​nm and a plasmonic resonance with a maximum at 376 ​nm. The second route was the hydrothermal method, in which aniline was used to reduce the metal salt and stabilize the nanoparticles; this provided a pink solution of nanoparticles with an average particle size of 11 ​± ​5 ​nm, and a plasmon resonance with a maximum at 550 ​nm. Aniline was polymerized by using hematin as the catalyst, and FT-IR, RAMAN, and NMR spectroscopy were used to characterize the structure. In addition, the PANI/AgNP composite was synthesized, and it exhibited a higher conductivity of 0.28 ​S/cm relative to that of PANI (0.05 ​S/cm).